What is CVE-2026-42421?

CVE-2026-42421 is a medium-severity vulnerability in Openclaw, classified under Insufficient Session Expiration. CVSS score: 5.4/10. Published 2026-04-28.

How severe is CVE-2026-42421?

Medium severity. CVSS v3 base score is 5.4 out of 10.

Vulnerability in Openclaw

CVE-2026-42421

OpenClaw before 2026.4.8 contains a session management vulnerability where existing WebSocket sessions survive shared gateway token rotation. Attackers can maintain unauthorized access to WebSocket connections after token rotation by explo…

EPSS: 0.000 (10.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N.

Affected products

Openclaw — versions 0, 2026.4.8

Weakness classification (CWE)

CWE-613 — Insufficient Session Expiration

References

GitHub Security Advisory (GHSA-5h3f-885m-v22w) (vendor-advisory, Vendor Advisory)
Patch Commit (Patch, patch)
VulnCheck Advisory: OpenClaw < 2026.4.8 - WebSocket Session Persistence via Shared Gateway Token Rotation (Third Party Advisory, third-party-advisory)

Frequently asked questions

What is CVE-2026-42421?: CVE-2026-42421 is a medium-severity vulnerability in Openclaw, classified under Insufficient Session Expiration. CVSS score: 5.4/10. Published 2026-04-28.
How severe is CVE-2026-42421?: Medium severity. CVSS v3 base score is 5.4 out of 10.